Related Articles

But this is the first time a comparative study has been made on the protective effects of black tea, by far the most popular variety drunk here.

Britons drink 168 million cups of black tea a day, although most of us put a splash of milk in it.

While laboratory studies have hinted black tea might protect the brain against age-related decline, there has been limited evidence from human studies to support the theory.

In the latest study, experts at the University of Singapore studied the lifestyle habits of 2,500 people aged 55 or over and recorded how much tea they drank.

Each volunteer also underwent a test to measure their cognitive function, or the 'fitness' of their brain.

When the experiment was repeated two years later, the researchers found those drinking the most black tea were least likely to have suffered cognitive decline, an early warning sign for dementia.

Drinking two to three cups daily reduced the risk of illness by around 55 per cent, while in heavy tea drinkers – those on six to ten cups a day – it was 63 per cent, according to a report in the American Journal of Clinical Nutrition.

Coffee drinkers, on the other hand, saw either no benefit or a tiny increase in their risk of dementia.

The researchers said: "Because tea is cheap, non-toxic and widely consumed, it has huge potential in promoting cognitive health and perhaps delaying the onset of dementia."

It is believed polyphenols could work in two ways: firstly by preventing oxidation of brain cells; and secondly by blocking the build-up of brain deposits, called plaques.

These are thought to inhibit proper brain function and lead to dementia and Alzheimer's.

Once the humble cuppa was prized mainly for the stimulant effect of its caffeine.

But numerous studies recently have found it has a myriad of health benefits.

Research has shown it can help lower cholesterol, reduce blood clots, and lower the chance of developing certain cancers.